Safety device for grinders



2' Sheets-Sheet 1 A ril 25, 1933. c; T. RAULE SAFETY DEVICE FOR GRINDERSFiled March 2, 1929 A TTORNEY INVENTOR 0/4 TZPau/e A ril 25, 1933. c."r; RAULE 1,905,651

SAFETY DEVICE FOR GRINDERS 4 Filed March 2, 1929 2 Sheets-Sheet 2 IN VENTOR- A TTORNE Y Patented 1933 PATENT 0FFlCE- CLIFFORD '1. RAULEQOI'BBOOKLINE, PENNSYLVANIA.

sum nnvrcnron enmnnns Application filed Iaroh 2.1929. Serial No.343,878.

My invention relates to internal grinding Describing in illustration andnot in limimachines with particular reference to an automatic safetydevice.

A purpose of my invention is to revent the wheel unit ortions of the inividual grinder units 0 a multiple unit internal grinder from moving tonormal. inding position if the conditions are not rlghtfor grinding,either by reason of the wheel Having finally worn away to a redeterminedlimit of safety or by reason 0 a work piece having been insertedimperfectly into the work-holder portion of the unit.

A further pur ose is to latch the grinding wheel portion 0 any grinderunit of a multiple spindle grinder away from its. normal grindingposition by an engagement between an imperfectly inserted work piece andlatch operating'mechanism having preferably either electric ormechanical connection with the latch.

A further pur ose is to latch the grinding wheel portion 0 any grinderunit of a multiple spindle grinder away from its normal grindingposition by the engagement between normally spaced members supportedrespectively upon the wheel unit and its slideway carrier, and operatingpreferably either electrically or mechanically to hold the unit from itsnormal grinding osition.

Further purposes will appear in t e specification and in the claims.

I have elected to show two only of the 'many difierent forms in which myinvention may be embodied, selecting forms that are efiicient inoperation, inexpensive to manufacture and which will illustrate theprinciples of my invention.

Figure 1 is a broken and somewhat diagrammatic top plan view of amultiple spindle internal grinder having applied to it one form of myinvention.

Figure 2 is a verticalv section-of Figure 1.

Figure 3 is an enlarged vertical section showing the same grindermachine as is seen in Figure 2 but having applied to it a different formof my invention.

Like numerals refer to like parts in all figures.

tation and referrin to the figures:--

I have illustrate my invention embodied on one of the forms of multiplegrinder shown in my copending a plication No. 126,- 403-entitled GrinderMi led August 2, 1926. The invention is applicable 7 to multiplegrinders of widely different types, but showing it embodied'with a form0 grinder disclosed and described in detail in said application makes itless necessary to go into detailed description of structure that is initself not part of the present invention. The ,mvention is well adaptedfor use with any one of the forms shown in said application, and to manyother forms of grinders not there shown.

Multi le machine The grinding machine is intended to operate uponduplicate work pieces which are continuously fed to grinder units of themachine as. the pass a loading oint and are discharged 0111 the sameumts after having been ground to finished size as the units pass anuhloading point preparatory to again reaching the loading point.

The machine :com rises a plurality of grinding units space around aturn-table that is mounted upon suitable stationary supportingstructure. The grinding operations at each unit begin when-the unitreceives a work piece as it passes the charging or loading point andfinally end at the unit with the removal of the finished work piece fromthe unit while the unit is passing the unloading point.

Each grinder unit comprises a work-holder unit adapted to rotate duringthe travel of the turn-table and a wheel unit adapted to present arapidly revolving and vertically .traversing grinding wheel to the workthroughout the grinding portion of the orbit.

A common feed cam mounted upon the stationary supporting structurecauses the traversing wheels to" travel successively around the sameorbit. The wheels initiall enter the work interiors out of contact witthe work surfaces and feed progressively at some point before theunloading grinding begins.

to a predetermined finish size. This occurs has been reached. There thewheel units successively rise to be out of the way for the unloading andsubsequent loading operations. ey-remain raised until they reach a pointsomewhat beyond the loading point in the direction of travel, and thenagain move down for traverse grinding.

My safety device is adapted to operate upon the individual units whileassing a paint of their common orbit that 1s located yond theloadingpoint but not so far beyond it. as is the point at which traverse In theillustration the turn-table 5 is pivoted upon a stationary central post6 of stationary supporting structure 7 and is rotated by a suitablemotor 8 mounted upon the base of the central post and geared at 9to-rotate the turn-table.

The work-holders 10 may be of any suitable type and are showncontinuously rotated by individual motors 11 mounted upondowncooperating engagement between a commonwardly extending portions 12of the turn table and holders.

Each wheel unit l t-"1s supported in a horizontal guideway 15 thatextends outwardly from a carrier 16 with which it is rigidly connectedand the individual carriers 16 are adapted to vertical reciprocationalong vertical traverse guideway standards 17 of the turn-table. v

The grinding unit carrier 16 is'positioned geared at 13 to therespective and traverse motion of the wheel 1s eflected ,by cooperatingengagement between a suitable stationary upwardly directed undulatorycam'18 surrounding the central axis of the turn-table and rods 19. Theserods ing lugs 20 of the carriers 16, through suitable perforations21- inthelower portion'ofthe turn-table to rest upon the cam surface 18. v

The wheel units are fed to the work by a cam 22 mounted 'upon thestationary supporting structure, and the outer ends of the feedrods 23adjustably threaded into the individual wheel units.

I guideways.

As thewheel wears away, by reason of grinding and diamonding, the feedarms 23 must be gradually lengthened to maintain station.

. the

safety device adapted to o asslngbetween the "grinding-to exact size.This lengthenin is conveniently effected automatically by a eedengagement between the teeth of the star wheels 25 and one or moreprojecting pin or pins 26 on the supporting structure, the wheel beingdesirably diamonded after such feed to insure exactly proper alinementof rinding element. 7 A l of the foregoing has beendescribedin greaterdetail in my prior 'application.

The present invention is directed at. a rate upon the individual unitswhile positions for feeding 1n new work pieces and that for the initialentry of the wheels for traverse grinding. In the plan view Figure 1 thework pieces are fed into the successive holders at a suitable platform27 and traverse grinding normally begins at some point 28 that is'somelittledistance beyond the position for feeding in the new work pieces.

The improper condition for grinding'may result from an imperfectinsertion ofla work piece or from a grinding wheel hav-' effectivegrinding.

In either case my device prevents the wheel unit from moving down intothe posiplatform 29 placed suitably back of the loading platform, thewheel carrier is raised into position to lift 'the wheel out of the wayabove the work-holders and it normally remains in its raised positionuntil some time after a new work piece has been inserted and until thepoint 28 is reached.

I mount a movable arm 30 across the common path of the upwardlyprojectin ends 31 of the work piecesin a position t at is somewhatbefore the point 29 at which the wheel carrier normally starts downfor-traverse grinding, and somewhat after the loadingposition 27.

The arm 30, conveniently pivoted to a lug 32 of the stationarysupporting structure, presents an upward bevel 33 toward the approachingwork pieces, riding over their projecting ends with or without contact.

The workpieces that have been properly positioned in their respectivehplders pass under the arm 30 without lifting it to any material extent.1

If however a work piece has not" been properly inserted inits holder itslower end does not lie flush with a circumferential seat (not shown)provided for it in the holder. As a result the upper end of the pieceprojects abnormally and when the piece.

passes under the arm it raises the arm to a greater extent than is thecase when the piece is roperly seated in its holder. fuse this abnormalmovement of the arm 30, which takes place only .in the event of 5 animproper seating of the work piece to prevent the usual return of thecarrier 16 to its position for traverse grinding.

I do this in any suitable way, in Fi re 2.

closing an electric circuit to electrica' y opo erate a latch 34 andinFi 3 using the upward movement of the arm to mechan bracket '38 on theturntable and carries a.

lower book 39 adapted to swing under a downwardly directed abutment 40when the ma et is energized.

he carrier is normally supported and traversed by the rod 19 the bottomof this rod resting upon the surface of the traverse cam 18. When thebottom of the rod reaches the descending portion 41 of the traverse cam,the carrier normally thenmoves down into position for traverse grindingbut if an abnormal condition at the unit has operated the latch, thecarriers abutment 40 comes down upon-the hook 39 which then supports thecarrier, the bottom of the rod remaining somewhat abovethe upwardlypresented surface of the cam.

The latch may be made operative under any number of diiferentcontingencies likely to produce abnormal conditions at the unit.

Of these different contingencies the most usual is that of an imperfectseating of a work piece in its holder and that of a wheel havinggradually wornaway to an extent that it is no longer effective toproperly grind and in Figure 2,1 show the same latch 34 operated ifeither one of these contingencies take place.

As the wheel gradually wears away the position of the wheel unit alongits horizontal guidewa is gradually changed, the wheel unit being edinwardly along its guideway by the star wheel 22 which engages the feedpin 26. w V v 'After the wheel has been reduced in size to apredetermined limit contact members 42 and 43 respectively mounted uponthe wheel unit and its carrier make contact, closing an electric circuitthrough the magnet 36 and operating the latch to prevent the return ofthe carrier to grinding position after the insertion of a work piece.

55 -It will be noted that in the illustration the individualelectromagnets 36 are connected in parallel to a suitable battery 44.The other side of the battery is grounded at 45 and the other side ofthe magnet goes to ground through the contact members 35 when there hasbeen an imperfect insertion of a work piece or through the contacts 42and 43 if the wheel is wornaway to its predetermined lower limit.

In the structure shown in Figure '3, I use mechanical means foroperating the latch latches may be operated by the different abnormalconditions under which it is desired to prevent the return of the wheelunit to its grinding position.

The latch 34' comprises a bell crank rock- ,34' and illustrate that thesameor separate er pivoted at 46 to a portion of the tlll'n- 1 table andpresenting an upwardl extending arm: 47 to engage the carrier an ahorizontal outwardly extending arm 48 to be engauged by the inner endofthe arm 30:

The hub of the rocker is provided with adj acent V-notches 49 and 50that alternatively receive the. beveled end of a click member 51 sring-pressed into one or other of the note es.

. The click member is normally in the lower notch and in this positionthe upwardly pre sented arm 47 is out of the way of the carr1erpermitting the carrier to move down to grinding position withoutstriking.

The arm 30 is preferably angularly adustable at 52 as to initialposit-ion, which s set so that the work pieces properly seated in theirrespective holders successively engage without materially raising thearm.

If a work piece is inserted imperfectly in its holder its top undulyprojects upwardly, raislng the arm 30 as it passes under which in turnangularly deflects the rocker bringmg the upper notch 49 into positionto receive the cllck member 51 which further defleets the rocker into aposition at which the top of the vertical arm 47 is latched under adownward abutment 40' of the carrier, preventing the carrier from goingdown into position fortraverse grinding.

In Figure 3 the carrier is provided with a horizontal bolt 53 providedwith adjacent V- notches 54 and 55 that alternatively receive thebeveled end of a click member 56-springpressed at 57 into one or otherof the notches.

The point of the click is normally in the right-hand notch and the bolt53 does not any wheel unit safely away from its carrier from moving downto position for. traverse grinding.

' abnormal conditions under which the wheel is maintained safely awayfrom grinding position have been an imperfect seating of the work piecein its holder and the reduction in size of the wheel through use to apredetermined limit beyond which it is considered inadvisable to use thewheel for grinding.

These two abnormal conditions are the most usual ones that make itundesirable to .permit the grinding wheel to descend to grindingposition, and while I have not illustrated the invention applied foroperation in the presence of other disadvantage ous abnormal conditionsI contemplate doing so whenever such conditions arise.

In view of my invention and disclosure variations and modifications tomeet individual whim or particular need will doubtless become evident toothers skilled in the art, to obtain all or part of the benefits of myinvention without copying; the structure shown, and I, therefore,-claimall such in so far as they fall within the reasonable spirit and scopeofmy invention. Having thus described my invention, what I claim as newand desire to secure by Letters Patent is 1.;In ;a multiple grinder, aturn-table, grinding units mounted on the turn-table spacedtherearound,each unit comprising a revolving work-holder and a grinding wheel,supporting structure for the turntable having unloading and loadingpoints for the units adjacent oneside of the table, and mechanism formoving the wheels suscessively away from the grinding position beforethe unloading point-isreached and back into grindingposition afterthe'loading point has beenlpassed, in combination with a safety devicefor preventing the movement of a grinding wheel to its grinding positionpreparatoryto initially grind ing the work and operative by meansof anabnormal condition at the unit.

2. In a multiple grinder, a turn-table,

grinding units-mounted on the turn-table spaced therearound, each unitcomprising a revolving work-holder and a grinding wheel, supportingstructure for the turntable having unloading and loading points fortheunits adjacent one side of the table, and mechanism for-moving" thewheels successively. away from the grinding position before theunloading point is reached and prevent a grinding revolving work-holderand a grindin wheel,

supporting structure for the turn-ta 1e having unloading and loadingpoints for the units adjacent one side of the table, and mechanism formoving the wheels successively away from the grinding position beforethe unloading point is reached and back into grinding position after theloading point has been passed, in combination with mechanism adapted tomovement of the wheel to its grinding position preparatory to initialgrinding comprising a latch, connections between the latch and wheeladapting the latch to maintain the wheel in raised position, anelectromagnet adapted to operate the latch, an electric circuit adaptedto operate the magnet and contact means for closing the circuitoperative preparatory to initial grinding and after loading by anabnormal condition of the unit. I

4. In a multiple grinder, a turn-table, grinding units mounted on theturn-table spaced therearound, each unit comprising a revolvingwork-holder and a grinding wheel, supporting structure for theturn-table having unloading and loading points for the units adjacentone side of the table, and mechanism for moving the wheels successivelaway from the grinding position before the unloading point is reachedand back into grinding position after the loading point has been passed,in combination with mechanism adapted to prevent the movement of thewheel to its grinding position comprising a latch, connections betweenthe latch and wheel adapting the latch to maintain the wheel in raisedposition, an electromagnet adapted to operate the latch, an electriccircuit adapted to operate the magnet, and contact means for closing thecircuit operative by. an abnormal extension of a work piece if the workpiece is imperfectly seated in its holder and other contacts for closingthe circuit operative by an inward extension of the wheel unit whenthewheel is worn away to a predetermined limit. a

5. In a multiple grinder, a turn-table, grinding units mounted on theturn-table spaced therearound, each unit comprising a revolvingwork-holder and a grinding wheel, supporting structure for theturn-table having unloading and loading points .for the ,units adjacentone side of the table, mechainto its position prevent the nism formoving the wheels successively away from the grinding position beforethe unloading point is reached and back into grinding position after theloading point has adapted to prevent the movement of the wheel to itsgrinding position including a latch to maintain the wheel in raisedposition, an electromagnet to operate the latch, an electric circuit,and contact means for closing the circuit operative by a work piece ifthe work piece is imperfectly seated in its holder and other contactmeans for closing the circuit operative by the wheel unit when the wheelunit reaches a predetermined position upon its carrier.

6. In a multiple grinder, a turn-table, grinding units mounted on theturn-table spaced therearound, each unit comprising a revolvingwork-holder and a grinding wheel, supporting structure for theturn-table having unloading and loadin points forthe units adjacent oneside 0 the table, and mechanism for moving the wheels successively awayfrom the grinding position before the unloading point is reached andmoving 'it back into grinding position after the loading point has beenpassed, in combination with a click latch adapted to latch the car rierin raised position and means operative by an abnormal condition at theunit for. operating the latch.

7. In a multiple grinder, a turn-table, grinding units mounted on theturn-table spaced therearound, each unit comprising a revolvingwork-holder and a grinding wheel, supporting structure for theturn-table having unloading and loading points .for the units adjacentone side of the table, mechanism for moving the wheels successively awayfrom the grinding position before the unloading point is reached andmoving it back into grinding position after the loading point has beenpassed in combination with a click latch adapted to maintain the carrierin raised position, and means operated by the upper end of a work pieceif the work piece has been imperfectly seated in its holder foroperating the latch.

8. In a multiple grinder, a turn-table, grinding units mounted on theturn-table spaced therearound, each unit comprising a revolvingwork-holder and a grinding wheel, supporting structure for theturn-table having loading and unloading points zfor the units adjacentone side. of the table,.and mechanism for moving the wheels successivelyaway from the grinding position before the unloading point is reachedand .back into grinding position after the loading point has beenpassed, in combination with a safety device adapted to prevent the 9. Ina multiple grinder, a turn-table, grinding units mounted on theturn-table spacedtherearound, each unit comprising a revolvingwork-holder and a grinding wheel,

been passed, in combination with mechanism supporting structure for theturn-table having loading and unloading pomts for the units adjacent oneside of the table, and mechanism for moving the wheels successively awayfrom the grinding position beforethe unloading point is reached and backinto grinding position after the loading the latch.

CLIFFORD T. RAULE.

return of a grinding wheel to its grinding position when the wheel hasworn away to a v predetermined limit.

